Tigers boss Richard Cockerill has admitted that the club face a battle to retain their top players within the constraints of the salary cap.

The Tigers boss said on Thursday that he is optimistic that England lock Geoff Parling will still be at the club next season but Steve Mafi's future is more uncertain. Mafi arrived at the Tigers back in 2010 but has established himself as an integral part in their team and is now reportedly on the radar of clubs in France and Japan.

With Top 14 sides and Japan's elite able to offer wages in excess of what is available in the Aviva Premiership, Cockerill concedes that Mafi could leave the club if the price is right.

"Steve Mafi is a very different player now to the one who joined us," Cockerill told the Leicester Mercury. "If he was English, the fuss people would be making about him would be incredible.

"To be able to do the things he does at his age would attract huge interest and he would be in the running for a place in the national team. Because he is Tongan, the attention he receives is a lot more low-key. As it is, Steve will attract lots of interest from France and especially Japan because that is halfway home for him. The money players like Steve could get out there would be considerable.

"Look at Alesana Tuilagi last season. He received an offer from Japan which we didn't even try to compete with because it would have taken up 25 per cent of our salary cap alone. It is getting harder and harder to keep the people we have got at this club.

"The salary cap means that, from this year to next year, we could have exactly the same squad. But the players who are out of contract will be 25 per cent more expensive because that is the nature of it. Wages are going up because the market place demands it.

"For each individual, their contract is really important to them and I understand that. But if we add just £5,000 on to each player's contract as a sweetener to try and make them sign again, that adds up to a lot of money. The trouble is that the £4.5m salary cap I have to spend stays the same."

But while Mafi could depart to pastures new, Cockerill is optimistic that former Bath and Brumbies openside Julian Salvi will remain at Welford Road. "Julian Salvi is near completion now," Cockerill said. "It is yet to be signed but it is pretty close. We have been talking to guys like him and George Ford for months.

"Jules compliments our back-row nicely and he has been really good for us. The openside flanker role is good for us now and, historically, we have always had strong players in that position like Lewis Moody, Neil Back and Josh Kronfeld.

"And these days, there are not shelf-fulls of out-and-out sevens in the market. In the Premiership, I can think of Jonathan Poff (Wasps) and Andy Hazell (Gloucester) and that's about it."